sleep會被其它訊號(SIGALRM,SIGINT)喚醒的測試

在應用程式中使用了sleep函數和訊號處理，現在有個問題，一但收到訊號就造成sleep函數中斷，延時就不足。這個問題該如何解決呢？

 

方法

#include <stdio.h>

#include <unistd.h>

#include <signal.h>

int sleep_with_restart(int second);

void signal_handler_int(int s);

void signal_handler_alarm(int s);

int sleep_with_restart(int second)

{

    int left;

    left = second;

#if 0 //case 1, sleep can be wake up by alarm or Ctrl + C, and the function will exit

    left = sleep(left);//sleep()被中斷之後會返回剩餘的秒數

#endif

#if 1 //case 2, sleep can be wake up by alarm or Ctrl + C, but we can restart it! because the sleep function will return the left second after be wake up!   

    while (left > 0)

    {

        fprintf(stdout, "Restarting sleep(%d) .../n", left);

        left = sleep(left);//sleep()被中斷之後會返回剩餘的秒數

    }

#endif

    return 0;

}

void signal_handler_int(int s)

{

    fprintf(stdout,"Caught signal SIGINT %d .../n", s);

}

void signal_handler_alarm(int s)

{

    fprintf(stdout,"Caught signal SIGALRM %d .../n", s);

}

int main(int argc, char **argv)

{

    signal(SIGINT, signal_handler_int);

    signal(SIGALRM, signal_handler_alarm);

    alarm(3);

    sleep_with_restart(10);

    return 0;

}